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Fischer D.,Ludwig Maximilians University of Munich | Klapotke T.M.,Ludwig Maximilians University of Munich | Reymann M.,Ludwig Maximilians University of Munich | Schmid P.C.,Ludwig Maximilians University of Munich | And 2 more authors.
Propellants, Explosives, Pyrotechnics | Year: 2014

Sodium 5-cyanotetrazolate sesquihydrate (1) was prepared from sodium azide and two equivalents of sodium cyanide under acidic conditions. Sodium 5-cyanotetrazolate sesquihydrate (1) reacts with hydroxylammonium chloride to form 5-aminohydroximoyl tetrazole (2). 5-Aminohydroximoyl tetrazole (2) is treated with sodium nitrite and hydrochloric acid to form 5-chlorohydroximoyl- tetrazole (3). The chloride azide exchange yields 5-azidohydroximoyl-tetrazole monohydrate (4). When compound 4 is treated with hydrochloric acid, 5-(1H-tetrazolyl)-1-hydroxytetrazole (5) is obtained in good yield. Compound 5 can be deprotonated twice by various bases. Different ionic derivatives such as bis(hydroxylammonium) (6), bis(hydrazinium) (7), bis(guanidinium) (8), bis(aminoguanidinium) (9), bis(ammonium) (10), and diaminouronium (11) 5-(1-oxidotetrazolyl)-tetrazolate were synthesized and characterized. With respect to energetic use salts 6 and 7 are most relevant. Compounds 3-9 and 11 were characterized using low temperature single-crystal X-ray diffraction. All compounds were investigated by NMR and vibrational (IR, Raman) spectroscopy, mass spectrometry and elemental analysis. The thermal properties were determined by differential scanning calorimetry (DSC). The sensitivities towards impact (4: 4 J, 5: 40 J, 6: 12 J, 7: 40 J), friction: (4: 60 N, 5: 240 N, 6: 216 N, 7: 240 N), and electrical discharge (5: 0.40 J, 6: 0.75 J, 7: 0.75 J), were investigated using BAM standards and a small scale electrostatic discharge tester. The detonation parameters of 5-7 were calculated using the EXPLO5.06 code and calculated (CBS-4 M) enthalpy of formation values. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Elbeih A.,University of Pardubice | Elbeih A.,Military Technical College | Pachman J.,University of Pardubice | Zeman S.,University of Pardubice | And 2 more authors.
Propellants, Explosives, Pyrotechnics | Year: 2013

A series of plastic bonded explosives (PBXs) based on Viton A and Fluorel binders were prepared using four nitramines, namely RDX (1,3,5-trinitro-1,3,5- triazinane), β-HMX (β-1,3,5,7-tetranitro-1,3,5,7-tetrazocane), BCHMX (cis-1,3,4,6-tetranitro-octahydroimidazo-[4,5-d]imidazole), and ε-HNIW (ε-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane). The detonation velocities, D, were determined. Detonation parameters were also calculated by means of modified Kamlet & Jacobs method, CHEETAH and EXPLO5 codes. In accordance with our expectations BCHMX based PBXs performed better than RDX based ones. The Urizar coefficient for Fuorel binder was also calculated. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Klapotke T.M.,Ludwig Maximilians University of Munich | Penger A.,Ludwig Maximilians University of Munich | Pfluger C.,Ludwig Maximilians University of Munich | Stierstorfer J.,Ludwig Maximilians University of Munich | Suceska M.,Brodarski Institute
European Journal of Inorganic Chemistry | Year: 2013

There are great demands to develop explosives with higher performance accompanied by reduced sensitivities towards external stimuli, higher thermal stability and improved environmental acceptability. This contribution presents modified nitramines, which were investigated by nucleophilic substitution reactions of potassium salts of 5-amino-3-nitro-1,2,4-triazole, 3,5-dinitro-1,2,4-triazole, 3,5-dinitroimidazole, 2,4-dinitroimidazole, 4-amino-3,5-dinitropyrazole, 3,5-dinitropyrazole, 3,4-dinitropyrazole and 3,4,5-trinitropyrazole on 1,3-dichloro-2-nitrazapropane. The energetic compounds were comprehensively characterized and their detonation parameters were calculated by the EXPLO5 code. Heats of formation were calculated by the atomization method using CBS-4M electronic enthalpies. The presented compounds show detonation performances comparable to pentaerythritol tetranitrate (PETN). In addition, they possess high thermal stabilities and low sensitivities, which make them interesting for further investigations and possible applications as insensitive, high-energy dense materials. The synthesis of advanced open-chain nitramines by nucleophilic substitution reactions with potassium salts of amino and/or nitro substituted 1,2,4-triazoles, imidazoles and pyrazoles on 1,3-dichloronitrazapropane yields neutral energetic materials. The energetic compounds were characterized in detail as secondary explosives. Interesting trends in safety and performance values were explored. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Aas B.,Ludwig Maximilians University of Munich | Kettner M.A.,Ludwig Maximilians University of Munich | Klapotke T.M.,Ludwig Maximilians University of Munich | Suceska M.,Brodarski Institute | Zoller C.,Ludwig Maximilians University of Munich
European Journal of Inorganic Chemistry | Year: 2013

In this work, the syntheses of 2,2,2-trinitroethyl-(2-nitro-2-azapropyl) carbamate (5), its analogue 2-fluoro-2,2-dinitroethyl(2-nitro-2-azapropyl) carbamate (6), and the corresponding 2,2,2-trinitroethyl(2-nitro-2-azapropyl) nitrocarbamate (7) and 2-fluoro-2,2-dinitroethyl(2-nitro-2-azapropyl) nitrocarbamate (8) are presented. The compounds were characterized thoroughly by vibrational spectroscopy (IR and Raman), multinuclear NMR spectroscopy, mass spectrometry, elemental analysis, differential scanning calorimetry measurements and single-crystal X-ray diffraction. In addition, the hitherto unknown low-temperature crystal structures of the starting materials 2-nitro-2-azapropyl chloride (1) and 2-nitro-2-azapropyl isocyanate (2) are presented. Owing to the positive oxygen balance of the carbamate derivatives, their suitability as potential oxidizers in energetic formulations with aluminium as the fuel is investigated and discussed. Standard enthalpies of formation were calculated at the CBS-4M level of theory. With these values and the experimental densities from room-temperature pycnometer measurements, several detonation parameters, such as the detonation pressures and velocities of the crude materials as well as the specific impulses of their formulations with aluminium, were computed by using the EXPLO5 (V6.01) computer program and compared with those of the corresponding mixtures with ammonium perchlorate as the oxidizer. Furthermore, the sensitivities towards impact, friction and electrostatic discharge were determined by using the BAM drop-hammer and friction tester as well as a small-scale electrical discharge device. Two new carbamates and the corresponding nitrocarbamates with 2-nitro-2-azapropyl, 2,2,2-trinitroethyl and 2-fluoro-2,2-dinitroethyl moieties have been synthesized and fully characterized. Owing to their positive oxygen balances, the carbamate derivatives have been evaluated as potential oxidizers in solid rocket propellants and their sensitivities towards mechanical stimuli have been determined. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Klapotke T.M.,Ludwig Maximilians University of Munich | Kurz M.Q.,Ludwig Maximilians University of Munich | Scharf R.,Ludwig Maximilians University of Munich | Schmid P.C.,Ludwig Maximilians University of Munich | And 2 more authors.
ChemPlusChem | Year: 2015

Sodium 5-cyanotetrazolate sesquihydrate (1) is prepared from sodium azide and two equivalents of sodium cyanide under acidic conditions. 1 is then N-oxidized with Oxone to sodium 5-cyanotetrazolate monohydrate (2). Compound 2 is treated with sodium azide and a Lewis acid to form 5-(1H-tetrazolyl)-2-hydroxytetrazole monohydrate (3). Compound 3 can be deprotonated twice by various bases to give ionic derivatives such as the bis(hydroxylammonium) (4), bis(hydrazinium) (6), bis(-guanidinium) (7), bis(aminoguanidinium) (8), bis(ammonium) ( 9), and diaminouronium (11) salt. In addition, compound 3 can only be deprotonated once, as demonstrated by the hydroxylammonium (4) and triaminoguanidinium (10) salts. Compounds 2-5 and 10-11 are structurally characterized by singlecrystal X-ray diffraction. Additionally, compounds 2-11 are characterized by using NMR and vibrational (IR, Raman) spectroscopy as well as mass spectrometry and elemental analysis. Their thermal behaviors are studied from differential thermal analysis measurements, and the sensitivities of the compounds toward shock, friction, and electrostatic discharge are determined. In addition, the heats of formation are calculated (atomization method, CBS-4M enthalpies), and several detonation/propulsion parameters are computed with the EXPLO5 code. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA. Source

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